Feature: 1.4Poles design, high torque & high efficiency. The overall efficiency exceed 90 percent. 2.Low heat production, long lifetime, strong overload protection and it can function 95% of its features without any heat sink appliance. 3.high quality materials adopted: high intense aluminum alloy anodizing shell , front & back cover , high-performance temperature-resistant magnetic steel and imported high-speed bearing Specifications: Model: 3670 Dimension: R36 * 70mm KV(RPM/V): 2150KV Poles: 4 Watts: 1600W Max voltage: Billy kikkok